Conventionally, fluororubber is used as a molding material for various seal parts used in high-temperature environments; however, along with a trend of higher-performance auto engines, there is an increasing demand for seal parts that can be used in much higher-temperature environments. Moreover, fluororubber has excellent heat resistance and oil resistance, but has inferior resistance to organic solvents such as ethers and ketones; thus, applications of fluororubber to parts for sealing such organic solvents are discouraged. Furthermore, due to its inferior chemical resistance, fluororubber cannot be used in cleaning rolls, rolls for copy machines and printers, and the like, to be in contact with alkali, acid, organic solvents, etc.
In order to compensate such defects of fluororubber, perfluoroelastomers are increasingly used in place of fluororubber. Perfluoroelastomers are often used in O rings; and the like that form seal parts by the themselves. In fact, however, they are rarely used in oil seals, rolls, valves; and the like combined with metal, because bonding methods thereof are not established. In addition, there are no commercially available vulcanizing adhesives suitable for perfluoroelastomers.
In response to this situation, the present applicant has previously proposed a perfluoroelastomer-laminated metal having improved interlayer adhesion, the perfluoroelastomer-laminated metal being produced by laminating an organic peroxide-vulcanized perfluoroelastomer layer via a vulcanizing adhesive layer comprising a silane coupling agent as a main component and an organic peroxide-vulcanized fluororubber layer sequentially formed on metal (see Patent Document 1). However, the laminated metal has two adhesive layers, i.e., the vulcanizing adhesive layer and the vulcanized fluororubber layer, increasing the number of production processes. This causes cost increase in industrial terms, so that a single adhesive layer is desired.